With advances in functions of electronic devices such as servers, a three-dimensional packaging technique is attracting attention as a packaging technique for semiconductor devices mounted on the electronic devices. The three-dimensional packaging technique is a technique of stacking a plurality of semiconductor elements in one semiconductor device and may achieve advances in functions of the semiconductor device.
The semiconductor device using the three-dimensional packaging technique is preferably provided with a heat dissipation mechanism for rapidly releasing heat generated in the plurality of semiconductor elements to the outside. Regarding the heat dissipation mechanism, there are air-cooling heat dissipation mechanisms which cool the semiconductor device by using outside air and liquid-cooling heat dissipation mechanisms which cool the semiconductor device by using coolant such as water.
Among them, as the liquid-cooling heat dissipation mechanism, there is proposed a type of heat dissipation mechanism in which a flow passage formed by finely processing a silicon substrate is arranged between the stacked semiconductor elements to efficiently cool the semiconductor device. However, due to technical difficulties, productization of such a heat dissipation mechanism has not been achieved.
Note that techniques relating to the present application are disclosed in Japanese Laid-open Patent Publication Nos. 2012-520575, 2008-153423 and 2005-180871.